Cornus Kousa Tree Named &#39;Melissa&#39;s Mountain Snowfall&#39;

ABSTRACT

A new and distinct cultivar of flowering dogwood tree, which has fused bracts is provided. This dogwood tree is botanically known as Cornus kousa and referred to by the following cultivar name: ‘Melissa&#39;s Mountain Snowfall’.

CROSS-REFERENCE TO A RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application Ser.No. 62/830,688, filed Apr. 8, 2019, the disclosure of which is herebyincorporated by reference in its entirety, including all figures, tablesand drawings.

This invention was made with Government support under Contract No.NACA-58-6062-6 awarded by the U.S. Department of Agriculture. TheGovernment has certain rights in the invention.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct dogwood cultivar,which has fused bracts. This dogwood is botanically known as Cornuskousa and hereinafter referred to by the following cultivar name:‘Melissa's Mountain Snowfall’.

This new dogwood cultivar was discovered in a planting of seedlings inthe University of Tennessee Arboretum in Oak Ridge, Tenn. ‘Melissa'sMountain Snowfall’ is a half-sibling of ‘Pam's Mountain Bouquet’ (U.S.Plant Pat. No. 25,575; Wadl et al., 2014, HortScience 49(9):1230-1233).Asexual reproduction of ‘Melissa's Mountain Snowfall’ has shown that theunique features of this new dogwood cultivar are stable and reproducedtrue-to-type in successive vegetative generations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1. Photograph of ‘Melissa's Mountain Snowfall’. Colors in thephotograph may differ from actual colors due to lighting and lightreflectance.

FIG. 2. Photograph of enlarged view of bracts on ‘Melissa's MountainSnowfall’.

FIG. 3. Photograph of the unripe fruit of “Melissa's Mountain Snowfall.”Also shown are the paper collars of the dried bracts that remain on thepetioles and around the fruit.

FIG. 4. Photograph of the ripe fruit of ‘Melissa's Mountain Snowfall’.FIG. 5. Photograph showing the exfoliating bark on the trunk of olderspecimens of ‘Melissa's Mountain Snowfall’.

DETAILED DESCRIPTION OF THE NEW VARIETY

A new and distinct cultivar of flowering dogwood having fused bracts isprovided. This dogwood tree cultivar is botanically known as Cornuskousa and referred to by the cultivar name: ‘Melissa's MountainSnowfall’. This cultivar exhibits insect resistance and diseaseresistance, particularly to powdery mildew caused by Erisphe pulchra.Dogwood anthracnose caused by Discula destructiva has never beenobserved on ‘Melissa's Mountain Snowfall’.

This new and distinct dogwood tree cultivar was discovered in a plantingof seedlings within the Arboretum at the University of Tennessee locatedin Oak Ridge, Tenn. The subject dogwood tree cultivar is a half-siblingof the Cornus kousa dogwood cultivar known as ‘Pam's Mountain Bouquet’.Table 1 shows the observed phenotypic similarities and differencesbetween the two cultivars.

TABLE 1 General phenotypic differences between the dogwood cultivars‘Melissa's Mountain Snowfall’ and ‘Pam's Mountain Bouquet’. (** = Keydifferences) ‘Melissa's Mountain Snowfall’ ‘Pam's Mountain Bouquet’About 80% of all bracts on About 82% of all bracts on the cultivarexhibit some the cultivar exhibit some degree of fusion degree of fusionResistance to Disease and Resistance to Disease and Insect Damage InsectDamage Exfoliating Bark in older specimens** No exfoliating barkInverted pyramidal growth habit** Spreading growth habit Multipleleaders** Single leader Six meters in height** 3-4 meters in height

In addition to the phenotypic differences listed above, it has also beenobserved that the alleles of the two cultivars differ at 5 of 8 selectedloci. Asexual reproduction of ‘Melissa's Mountain Snowfall’ by graftingof axillary buds onto seedling rootstocks has shown that the uniquefeatures of this new dogwood cultivar are stable and reproducedtrue-to-type in successive generations.

DETAILED BOTANICAL DESCRIPTION

The following observations, measurements and comparisons describe thecultivar ‘Melissa's Mountain Snowfall’ grown in Oak Ridge, Tenn. Treesused for this description were about thirty (30) years old. Planthardiness is expected to be zones 3-9. The color characteristicdescriptions use color references to The Royal Horticultural Society(R.H.S.) Colour Chart, The Royal Horticultural Society, London, UK,4^(th) Edition, 2001, except where general terms of ordinary dictionarysignificance are used. It has been determined that alleles differ at 5of 8 loci shared by ‘Melissa's Mountain Snowfall’ and ‘Pam's MountainBouquet’, as shown in Table 2.

TABLE 2 Allelic Comparison of ‘Melissa's Mountain Snowfall’ and ‘Pam'sMountain Bouquet’ at specified loci ‘Melissa's Mountain ‘Pam's MountainSnowfall’ (bp size Bouquet’ (bp size Locus for each allele) for eachallele) CK005* 228:228 222:247 CK072* 113:122 113:117 CK058* 152:152148:148 CK031 140:140 140:140 CK040* 102:102 94:94 CK029  90:102  90:102CK015* 119:122 130:136 CK047 128:128 128:128

Table 3 indicates the primer sequences and microsatellite markers (orsingle sequence repeats—SSR) in ‘Melissa's Mountain Snowfall’ comparedwith the same microsatellite markers (SSR) in ‘Pam's Mountain Bouquet.’Those loci indicated with an asterisk (*) differ between the twocultivars:

TABLE 3 Primer Sequences and Microsatellite markerscompared between ‘Melissa's Mountain Snowfall’and ‘Pam's Mountain Bouquet’ GenBank Microsatellite Repeat SequencesAcces- Repeat sion No. Locus Primer Sequence (5′-3′) Motif EU544308CK005* F: GCATTTGTCCTTTGTTTGACAT (AC)₂₀ (SEQ ID 1)R: TTTTTCGCGAAGTGTTCTCTAC (SEQ ID 2) EU125523 CK015*F: GTCAAATTTTTGATCTTTCTCTCT (CT)₁₀ (SEQ ID 3)R: GGAGAGACAGAGTACAGTAGAGGT (SEQ ID 4) EU125524 CK029F: AATTTAGGTTAAGGTTTTGATTTG (TC)₈ (SEQ ID 5) R: AGAGAGAATAGGTTACAGCATCAT(SEQ ID 6) EU125525 CK031 F: TGTCACTGCTTACAGAAACAAT (CT)₇ (SEQ ID 7)R: TATGACGAGATTGTATAAGTTGCT (SEQ ID 8) EU125526 CK040*F: CCAAGTCAGTTTGGTAGTAATTC (GT)₁₆ (SEQ ID 9) R: AGTGCAACTTTTACTTGCTATGT(SEQ ID 10) EU544309 CK058* F: CTTAAGTCACAAAGACAATGAAAT (GT)₁₀(SEQ ID 11) R: AAGAGAGTTCAGATTTATCTTTGC (SEQ ID 12) EU544312 CK072*F: AGCACTCATAGTCCTTGCAC (GT)₁₀ (SEQ ID 13) R: GTTAAAACGAAGAAGATACAACAA(SEQ ID 14) EU125528 CK047 F: GAAAGAGATAAAAGATGGTTCAAT (AC)₆ (SEQ ID 15)R: CTTATAGAGTAAGCCCACCATC (SEQ ID 16)

The cultivar ‘Melissa's Mountain Snowfall’ has some similarity inphenotypic characteristics to the cultivar ‘Pam's Mountain Bouquet’(Wadl et al., 2014). The following Table 4 provides a comparison of eachcultivar for those characteristics that have been observed. Measurementsare provided as an average (with ranges also provided as indicated):

TABLE 4 Characteristics of ‘Melissa's Mountain Snowfall’and Pam'sMountain Bouquet′ Color Descriptions are based upon the RoyalHorticultural Society's (RHS) colour chart, 4th Edition 2001. ‘Melissa'sMountain ‘Pam's Mountain Character Snowfall’ Bouquet’ 1 Tree formInverted pyramidal spreading (observation) 2 Tree height 5-6 meters low(observation) (about 3-4 meters; spread about 4 -5 meters, and dependenton age and environment) 3 Branch thickness Not observed medium(measurement) (age dependent) Thickness in the middle portion of a plant4 Color of current Not observed Green Shoot 143B (observation) currentshoot color in the middle portion of a plant 5 Branch color Mixture of156A, Greyed; Green (observation) 197B, and 198B 198B current branchcolor in the middle portion of a plant second year+ 6 Dark spots on Notobserved Absent Branch (observation) presence of dark spots on thebranch 7 Branching High High (observation) density of branching 8Internode length Not observed Short (measurement) Internode length inthe middle portion of a plant 9 Whole shape of Obovate Obovate leaves(observation) see FIG. 1 whole shape of a leaf in the middle portion ofa plant 10 Shape of leaf Acuminate Acuminate tip (observation) see FIG.2 Tip shape of a leaf in the middle portion of a plant 11 Shape of leafTruncate Truncate Base (observation) see FIG. 2 Base shape of a leaf inthe middle portion of a plant 12 Shape of leaf Entire Entire Margin(observation) shape of a leaf margin in the middle portion of a plant 13Leaf rolling Not observed Rolling inward (observation) see FIG. 4 14Leaf curvature Not observed Flat (observation) see FIG. 5 15 Leaf marginNot observed None Undulation (observation) 16 Leaf length Averages 87.1mm Long (measurement) (about 100-140 Length from the m) tip to the baseof mature leaf 17 Leaf width Averages 44.4 mm Narrow (measurement)(about 40-50 The maximum mm) width of mature leaf 18 Leaf thicknessMedium Medium (observation) Thickness of mature leaf 19 Bud color(observation) 138B, unopened; Grayish green Color of bud just 132D,opened 179A after sprouting 20 Immature leaf Not observed Light Greencolor (observation) 135B 21 Presence of Absent Absent anthocyanin(observation) Coloration by anthocyanin on the immature leaf upperside22 Color of leaf 143A Green upperside (observation) 143B Color of matureleaf upperside 23 Color of leaf 143C Light Green lowerside (observation)146B Color of mature leaf lowerside 24 Seasonal change Changed Changedof a mature leaf (observation) 25 Color of leaves in Red Red autumn(observation) 10C −46A 10C −46A 26 Leaf variegation Not variegated Notvariegated (observation)Variegation on leaf upperside 27 Variegation Notobserved NA pattern (observation); Pattern of variegation on a leafupperside 28 Variegation color Not observed NA (observation) 29 seasonalchange Not observed NA of variegation color (observation) 30 Hair onleaf None None upperside (observation) hair density on a mature leafupperside 31 Hair on leaf None None lowerside (observation) hair densityon a mature leaf lowerside 32 Petiole length Average about 10.4 Short(measurement) Length mm; unequal (about 15-25 from at base, about 5-7mm) the base of blade mm longer to the base petiole on one side 33Petiole width Medium (<7 mm) Medium (measurement) (<8 mm) The maximumwidth of a mature leaf petiole 34 Petiole color Green 143A Green(observation) 143B 35 Inflorescence type Umbel Umbel (observation) 36Inflorescence Upright Upright direction (observation) 37 InflorescenceAverage about 31.7 Medium diameter (observation) (diagonal mean length =74 mm.; mean width = 53 mm) 38 Flower diameter Not observed Small(measurement) 39 Floret diameter Not observed Small (measurement) 40Floret color Yellow Yellow (observation) 150A 150C 41 Bract type(observation) 80% are fused, but 83% are fused, variable (See Table) butvariable (See Table 3) 42 Uniformity of Not uniform Not uniform bractsize (observation) 43 Bract overlapping No overlap of No overlap of(observation) unfused bracts unfused bracts 44 Bract orientationRecurved, Reflexed, Recurved, (observation) or Flat Reflexed, or Flat 45Bract rolling Varies (may roll Varies (may roll (observation) inward oroutward inward or outward 46 Degree of bract Medium strong rolling(observation) 47 Bract curvature Varies Varies (observation) (can berecurved, (can be recurved, flat, or reflexed) flat, or reflexed) 48Bract twisting None None (observation) 49 Whole shape of Ovate Ovatebracts (observation) 50 Shape of bract Acuminate Acuminate apex(observation) 51 Unfused bract length Inner Bract Average Medium(measurement) 48 mm; Outer Bract Average 43 mm 52 Unfused Bract widthInner bract Average (measurement) 27 mm; outer bract average 28 mm. 53Number of bracts 4 FUSED; Diameter FUSED, but 4 (measurement) average89.5 mm 54 Bract color 157B 155A (measurement) (immature: 157A) 55 Bractvariegation Not variegated Not variegated (observation) 56 VariegationNA NA pattern (observation) 57 Variegation color NA NA (measurement) 58Pistil color (observation) Yellow green Not Yellow green coded Not coded59 Stigma color Dark Green Dark Green (observation) (Not Coded) (NotCoded) 60 Peduncle Medium Medium thickness (measurement) 61 Pedunclelength Average 69 mm Long (measurement) (mean of 68 mm) 62 Pedunclecolor Yellow green 143C Yellow green (observation) 144B 63 Fruit shape(observation) Globose Globose 64 Fruit length About 28.7-29.3 mm Medium(measurement) (about 40 mm) 65 Fruit width About 28.7-29.3 Medium(measurement) mm (about 4.0 mm) 66 Fruit color (observation) 134N, Fall;60D- Unripe:143B; 61A, when ripe Ripe 33B to 43A. Highly variabledepending on ripeness 67 Fragrance (observation) Absent Absent 68 Seedfertility Not observed High (observation) 69 Time to the first MediumMedium flowering (observation) (April-mid-May) (April-mid-May) 70Blooming habit Prolific Many (observation) 71 Flowering season Oneseason One season (observation) flowering 72 Flowering time About 5-6weeks About 5-6 weeks (observation) 73 Deciduous or Deciduous Deciduousevergreen (observation) 74 Cold hardiness To −20C Medium (observation)(to −20° C.-no effect) 75 Heat tolerance Strong Strong (observation) (to40° C.-no effect) (to 40° C.-no effect) 76 Pest resistance No specificpests Strong (observation) noted some spots of (no specific pests brownanthracnose, noted; 160A 77 Disease resistance Strong resistant toStrong resistant (observation) dogwood to dogwood anthracnose andanthracnose and powdery mildew: powdery mildew some spot some spotanthracnose anthracnose on especially on bracts especially on bracts 78Bark color exfoliating bark Grayed-Green 177b and 143C; 198B exfoliatedareas 199C-D 79 Bark texture Exfoliating Smooth 80 Angle of emerging 20°C.-35° C.from 20° C.-30° C. from branches vertical stem vertical stem 81Time to first leaf bud Mid-to late-April Mid- to late-April burst 82Leaf Vein color (bottom 145B Green-Greyed side) 192A 83 Immature Leafcolor Similar to fully Similar to fully expanded leaf color expandedleaf color 84 Bract base Truncate Truncate 85 Bract margin Entire Entire86 Vestiture Puberulous, Puberulous, reticulate reticulate 87 Flower/Mean =31 Mean = 34 inflorescensce number 88 Seed shape Flattened alongFlattened along length length 89 Seed color Greyed Yellow Greyed Yellow162D 162D 90 Seed number 0-17 per fruit 0-17 per fruit 91 Bloom duration3-5 weeks 3-5 weeks (dried, dead bracts (dried, dead are retained as abracts are “collar”on peduncle retained as a until fruit fall in“collar”on Autumn) peduncle until fruit fall in Autumn) 92 Time of fruitripening Begins in mid- Begins mid-to August and Ripe in late-AugustOctober through October 93 Trunk diameter (at base) Multiple stem 18 cmat 15 years variable. About 10- of age 14 cm; numerous lenticles; 94Anther color N79B Greyed-purple N186 95 Flower petal color Yellow-greenYellow-green 145C 145C 96 Style/Stigma description InconspicuousInconspicuous

Botanical classification: Cornus kousa ‘Melissa's Mountain Snowfall’.

Unique Features: This tree features prolific flowering and exhibitsfused bracts. About 80% of all bracts on the cultivar exhibit somedegree of fusion (one side, two sides or three to four sides beingfused), as shown in Table 5.

TABLE 5 Types of fused bracts observed on ‘Melissa's Mountain Bouquet’Not Two sides 3 sides Fully Year fused fused fused Fused 2016 29 23 1732 (n = 101) (29%) (23%) (17%) (32%) 2017 39 28 33 45 (n = 145) (27%)(19%) (23%) (31%) 2019  7 12 14 90 (n = 123) (6%) (10%) (11%) (73%) Mean25 21 21 55.7 (20.7%) (17.3%) (17.0%) (45.3%)

Disease susceptibility: None noted. Powdery mildew caused by Erisphepulchra was not observed. There was some minor occurrence of spotanthracnose caused by Elsinoe cornii observed in 2017-2019. Dogwoodanthracnose caused by Discula destructiva has never been observed on‘Melissa's Mountain Snowfall’.

Insect Damage: Minor insect damage on leaves.

REFERENCES

-   Wadl, P. A., M. T. Windham, R. E. Evans, and R. N. Trigiano. 2014.    Three new cultivars of Cornus kousa: Empire, Pam's Mountain Bouquet,    and Red Steeple. HortScience 49(9):1230-1233.

We claim:
 1. A new and distinct cultivar of Dogwood, Cornus kousa, named‘MELISSA'S MOUNTAIN SNOWFALL’, as illustrated and described.